HID: wacom: fix timeout on probe for some wacoms (8ffffd52) · Commits · 戴 / test

Some Wacom tablets (at least the ISDv4 found in the Lenovo X230) timeout during probe while retrieving the input reports. The only time this information is valuable is during the feature_mapping stage, so we can ask for it there and discard the generic input reports retrieval. This gives a code path closer to the wacom.ko driver when it was in the input subtree (not HID). Cc: stable@vger.kernel.org # requires cherry-pick of Signed-off-by:

Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by:

Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_sys.c

+16 −2

Original line number	Diff line number	Diff line
		@@ -110,12 +110,24 @@ static void wacom_feature_mapping(struct hid_device *hdev,
		{
		struct wacom *wacom = hid_get_drvdata(hdev);
		struct wacom_features *features = &wacom->wacom_wac.features;
		u8 *data;
		int ret;

		switch (usage->hid) {
		case HID_DG_CONTACTMAX:
		/* leave touch_max as is if predefined */
		if (!features->touch_max)
		features->touch_max = field->value[0];
		if (!features->touch_max) {
		/* read manually */
		data = kzalloc(2, GFP_KERNEL);
		if (!data)
		break;
		data[0] = field->report->id;
		ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
		data, 2, 0);
		if (ret == 2)
		features->touch_max = data[1];
		kfree(data);
		}
		break;
		}
		}
		@@ -1280,6 +1292,8 @@ static int wacom_probe(struct hid_device *hdev,
		if (!id->driver_data)
		return -EINVAL;

		hdev->quirks \|= HID_QUIRK_NO_INIT_REPORTS;

		wacom = kzalloc(sizeof(struct wacom), GFP_KERNEL);
		if (!wacom)
		return -ENOMEM;

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